TOU Calculators

Time-of-use (TOU) tariffs price electricity by clock and season. Peak afternoon blocks can cost several times off-peak overnight energy. Batteries, load shifting, and smart charging exist largely to exploit those spreads—if round-trip efficiency and cycling limits still leave savings after equipment cost.

Peak shaving targets maximum demand kilowatts, not just energy kilowatt-hours. Commercial bills may add demand charges based on the highest 15-minute interval each month. A single poorly timed HVAC start plus oven and EV charging can set an expensive ratchet for weeks.

Arbitrage math must include inverter losses, battery usable capacity, and minimum state of charge reserves for backup. Saving ten cents per kWh on paper means little if you only shift two kWh per day through a 90% efficient path.

Rate schedules change with regulators and utilities. Summer and winter peak windows differ. Re-run economics when your tariff version updates or when you add solar export credits.

WattQuick TOU calculators model simple peak/off-peak savings, estimate demand charge exposure from load peaks, and help compare timer-based load shifting versus battery assist. Validate against your actual interval meter data when available.